Process and apparatus for making paper covered electrical cable conductors



June 24, 1969 c, gfl ET AL 3,451,204

' PROCESS AND APPARATUS FOR MAKING PAPER COVERED ELECTRICAL CABLE CONDUCTORS 1 Filed March 29. 1968 Sheet of s INVENTORS CHRISTOPH CRAMER GUNTER KLUGE BY ERNST WOITKE ATTORNEY 3,451,204 ERED Sheet 2 coy ' c. CRAMER ET APPARATUS FOR MAKING PA ECTRICAL CABLE CONDUCTO PROCESS AND FIG.2

June 24, 1969 I c CRAMER ET AL 3,451,204

PROCESS AND APPARATUS FOR MAKING PAPER COVERED ELECTRICAL CABLE CONDUCTORS Filed March 29, 1968 Sheet 3 FIG. 3 FIG. 4

FIG. 5 FIG. 6

United States Patent 1m. (:1. noz s/sa, 3/08 US. Cl. 57-18 Claims ABSTRACT OF THE DISCLOSURE A method and apparatus for preparing paper strip insulation for application to conductors used to make up electric cables and the like comprising folding said paper strip, pressing and then combining with said conductors.

BACKGROUND OF THE INVENTION It is conventional to prepare paper dielectric in continuous strip form by flanging and folding one longitudinal edge thereof as the same is applied to the electric conductor forming part of communication cables and the like. For this purpose, the paper tape or strip is passed through a flanging device which may take the form of a flattened tubular die or curved yoke.

However, if the edges of the paper tape are precoated with wax to prevent tearing of the tape at high fabrication speeds, difliculties are encountered because of the deposit and collection of wax in the forming die or yoke. This in turn leads to an undefined tensile stress in the paper tape which interfere with the maintenance of electrical values required for proper operation of the communication cable. Also, it has been found that with such known apparatus, the flanging and folding action may shift from one edge of the tape to the other edge thereof. Further, with known procedures there is no assurance of uniformity in the width of the flanged and folded tape edge portions.

Accordingly, an object of this invention is to provide improved apparatus and methods for preparing paper tape or strip to have a folded longitudinal edge therein wherein the fold is produced by successive forming operations which insure limiting the folded tape edge to only one longitudinal edge of the tape and which assures a uniform width for the folded tape edge portion throughout the length thereof.

Another object of this invention is to provide apparatus and methods of the character described, which results in a precise, uniform tape dielectric for application to electrical conductors making up communication cables; the tape dielectric being adapted to maintain electrical parameters for the cable throughout the length thereof to assure optimum signal transmission. Thus, the individual, insulated conductors may be arranged in true symmetrical relation within the cable so as to avoid undesirable coupling phenomena.

Other objects of this invention will in part be obvious and in part hereinafter pointed out.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view, with parts in section, showing a paper tape preparing apparatus embodying the invention;

FIG. 2 is a front elevational view thereof;

FIG. 3 is an elevational view showing a pair of tape folding rollers;

3,451,204 Patented June 24, 1969 FIG. 4 is a view similar to that of FIG. 3, showing an alternative set of tape folding rollers;

FIG. 5 is a view similar to that of FIG. 3 wherein the pair of folding rollers treat both edges of the tape to provide reversely related folded edge portions; and

FIG. 6 is a view similar to that of FIG. 5, wherein the folding rollers provide for folding both edges of the tape in the same direction.

DESCRIPTION OF THE PREFERRED EMBODI- MENTS OF THE INVENTION As shown in the drawings, and particularly in FIGS. 1 and 2; apparatus embodying the invention is indicated at 10. The same comprises a revolving spinning head 11 of a conventional core spinner, not shown. A supply reel 12 of paper tape 13 is attached to the head 11 with a guide member 14 passing tape to a guide member 15 which directs the tape 13 upwardly to an edge flanging assembly generally indicated at 16.

Assembly 16 is mounted on spinning head 11 and rotates with it. Assembly 16 includes a bushing 17 slidably and adjustably mounted on one of the vertical standards 18 upstanding from spinning head 11. A roller mounting bracket 19 is fixed in spaced relation from bushing 17 and carries at its lower end a guide roller 20 having end flanges 21.

The bracket 19 also carries immediately above guide roller 20, a pair of edge folding rollers 22, 23. As shown in FIG. 3, roller 22 has a single flange 24 on one side thereof which clears a corresponding annular groove 24A in roller 23. Similarly, roller 23 has a single flange 25 oppositely related to flange 24 and which clears a corresponding annular groove 25A in roller 22. The spacing between opposed roller surfaces 26, 27 of rollers 22, 23 is equal to the thickness of tape 13. The paper tape 13 passing through rollers 22, 23 has the edge 13A folded through an angle of as shown in FIG. 3.

The paper tape 13, thus prepared, passes to a flanging roller 28 mounted on bracket 19 and located above rollers 22, 23. Roller 28 has flanges 29, 30 which have an axial spacing so as to be effective to flange over the previously folded tape edge portion 13A, to a flat folded, double thickness condition.

The thus folded tape 35 now passes for wrapping about conductor C moving upwardly from a supply reel, not shown. The flanging roller 28 may be supplemented by a calibrated nipple, not shown, which is applied to the freshly wrapped conductor C, which insures a uniform wrapping throughout the length of the conductor.

It is understood that the several rollers may be made up of laterally related discs, so that the apparatus may treat paper tapes of varying widths. Further, the width of the folded tape edge 13A may be varied by adjusting the axial extent of roller surfaces 26, 27 of rollers 22, 23.

It has been found that with folding and flanging rollers, as hereinabove described, the paper tape 13 may be transported at high speeds without damage or tearing of the tape edges. Further, the tape 35 is applied to conductor C with substantially tractive force so that a uniformly large air space is provided under the tape throughout the entire length thereof.

The spacing between flange 25 on roller 23 and the opposed portion of annular groove 25A of roller 22 is at least equal to the thickness of tape 13 to thereby receive folded tape edge portion 13A and perform the folding operation throughout the length of the tape 13 which rotates rollers 22, 23 as it moves therebetween. The spacing between flange 24 of roller 22 and the opposed portion of annular groove 24A of roller 23 is limited to prevent contact between said rollers and to limit the lateral extent of tape 13 so as to make for a uniform folding operation over the length of the tape.

As shown in FIG. 4, the pair of folding rollers 40', 41 differ from rollers 22, 23, shown in FIG. 3, by having roller 40 devoid of flanges and having annular grooves 42, 43 which clear flanges 44, 45 on roller 41. Here again, the spacing between flange 45 and the opposed portion of groove 43 is equal to the thickness of the tape 13 to allow for the edge folding operation, as previously described.

It may be desired to fold and flange both edges of the paper tape. In this case, apparatus includes a pair of rollers 50, 51, as shown in FIG. 5. Here the tape 52 passes between opposed roller surfaces 53, '54 dimensioned and related to flanges 55, 56 and their spacing relative to grooves 57, 58 as to fold tape edge portions 52A in opposite directions.

Alternatively, as shown in FIG. 6, the rollers 40, 41, are similar to that shown in FIG. 4, except that the opposed roller surfaces, flanges 44, 45 and grooves 42, 43 are dimensionally related to fold and receive both edges 52A of tape 52; the edges 52A extending in the same direction.

It is understood that when both edges 52A of paper tape '52 are folded, as indicated in FIGS. 5, 6; a pair of flanging rollers such as roller 28, shown in FIG. 1, will be required. Such flanging rollers may be arranged on either side of the tape to complete the folding operation initiated by folding rollers 40, 41; 50, 51.

Provision may be made for adjusting the distance between the opposed roller surface of the pair of edge folding rollers 22, 23; 40, 41; 50, 51, to accommodate tapes 13 of varying thickness,, using adjustable mounting means known in the art. Further, the rollers may have a hinged mounting to facilitate the insertion of tape 13 at the beginning of the operation.

What is claimed is:

1. Process for applying dielectric tape to an electrical cable conductor comprising moving said tape from a supply source to said conductor, continuously folding a longitudinally extending marginal edge portion of said tape through an angle of substantially 90, continuously flattening the folded marginal edge portion of said tape into contact with said tape and applying said edge folded and flattened tape to said conductor.

2. Process as in claim 1 wherein marginal edge portions at each of the side edges of said tape are folded through an angle of about 90, and continuously flattening each of said folded marginal edge portions.

3. Process as in claim 2 wherein said folded marginal edge portions of the tape extend in opposite directions.

4. Process as in claim 2 wherein said folded marginal edge portions of the tape extend in the same direction.

5. Apparatus for applying dielectric tape to an electrical cable conductor comprising means for guiding the movement of dielectric tape through a given path, a pair of opposed roller means having opposed roller surface portions for engaging opposite surface portions of said tape, said opposed roller means including means for folding at least one longitudinally extending marginal portion of said tape through an angle of about and single roller means for engaging the edge folded tape and flattening the folded edge portion of said tape, each of said roller means having at least one flange.

6. Apparatus as in claim 5 wherein each of said pair of roller means comprises a flange at one end thereof and an annular groove at the other end thereof, the flange of each of said pair of rollers being received in the annular groove of the other of said pair of rollers.

7. Apparatus as in claim 5 wherein the axial extent of the roller surface in each of said pair of roller means from the flange to the annular groove thereof is substantially equal to the original width of said tape less the width of the folded marginal edge portion thereof.

8. Apparatus as in claim 5 wherein the axial extent of the roller surface of each of said pair of rollers is adjustable to accommodate tapes of different original widths.

9. Apparatus as in claim 6 wherein the space between the flange of one of said pair of rollers and the opposed surface portion of the annular groove of the other of said pair of roller means is substantially equal to the thickness of said tape.

10. Apparatus as in claim 5 wherein said single roller means comprises at least one flange, the axial extent of the roller surface of said roller means from said one flange is of an order to flatten the folded marginal edge portion of said tape.

References Cited UNITED STATES PATENTS 750,563 1/ 1904 Anderson 156-54 1,376,914 5/1921 Ashbaugh et al 57-18 1,720,923 7/1929 Poole 270-94 2,001,546 9/1931 Pourtier 57-18 XR 2,507,589 5/ 1950 Ciambrone et al 57-18 3,193,904- 7/1965 Evans et a1. 57-31 XR DONALD E. WATKINS, Primary Examiner.

US. Cl. X.R. 57-167; 270-94 

